Automatic Starting Of Domains; Migrating Xen Vm Guest Systems - Novell LINUX ENTERPRISE SERVER 11 - VIRTUALIZATION Manual

4.5 Automatic Starting of Domains

If you need automatic starting of domains at bootup, or after a crash, the xend must be
configured to execute the desired behavior. There are five different situations that need
to be handled.
After boot of the Hypervisor
Set the xend variable on_xend_start to the desired value. For more details,
see
(on_xend_start start)
When shutting down xend
Xend can tell the VM Guest system to shut down. However, it does not check if
the guest was stopped when doing a system shutdown of Domain0. Thus, it is not
recommended to rely on this feature. Example:
(on_xend_stop shutdown)
When rebooting the VM Guest
Xend has control about what to do when a VM Guest does a reboot. By default, it
is restart the guest just as one would expect:
(on_reboot restart)
During poweroff of a VM Guest
When a guest is shut off, the xend by default destroys the guest without shutting
it down.
(on_poweroff destroy)
After a crash of the VM Guest
After a VM Guest crashes, the xend can restart the guest. This is also the default:
(on_crash restart)

4.6 Migrating Xen VM Guest Systems

With Xen it is possible to migrate a VM Guest system from one VM Host Server to
another with almost no service interruption. This could be used for example to move a
busy VM Guest to a VM Host Server that has stronger hardware or is not yet loaded.
Or, if a service of a VM Host Server is required, all VM Guest systems running on this
36 Virtualization with Xen
the section called "on_xend_start" (page 120). Example: